Functional properties in materials are an essential part of modern society, enabling a wide range of computing, information and sensor technologies. An example of functional materials are the magnetic ones, which is today used in several devices like hard drives for storing data, and sensors. In addition, magnetic properties have attracted a great deal of interest for new types of energy efficient device concepts. To improve these devices, and design new ones, there is a need to understand how these materials behave at nanometre length scales, since the interesting physics often arise there. However, there is a lack of experimental techniques for looking at the magnetic properties in these materials, especially at very small length scales. Another important factor is studying these properties across phase transitions. For example, magnetic materials become non-magnetic above certain temperatures, and seeing this change from magnetic to non-magnetic can reveal information about the underlying physical phenomena controlling device performance.
Scanning Transmission Electron Microscopy (STEM) is a powerful imaging technique, which can study materials down to single atoms. However, historically it has mostly been used to study the structure and composition of materials, not their functional properties such as magnetic fields. With recent advances in fast pixelated STEM detectors, it has become possible to directly image the magnetic fields. However, much work remains, both in making this work practically on most STEM instruments, and making the technique work across a range of materials.
MAGIMOX aimed to improve this, by utilizing the STEM in co-junction with the recently developed fast pixelated STEM detectors, to study both the structure and magnetic properties in perovskite oxide thin films. Thus the overall objective was to study these specific materials, however since these detectors were fairly new, a great deal of method and analysis software development was necessary.
